A.maintain radial alignment between the pump impeller and casing
B.absorb all impeller shaft end thrust
C.prevent water leakage to the atmosphere
D.prevent wear of the pump casing and/or impeller
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A.psychrometer
B.salinometer
C.anemometer
D.sphygmomanometer
A.A large change of viscosity occurs with a minor change in temperature
B.No change in viscosity occurs with any change in temperature
C.Very little change in viscosity occurs with a significant change in temperature
D.The viscosity of the oil increases with an increase in temperature
A.pump would be very noisy
B.pump would vibrate excessively
C.pump would develop insufficient flow
D.stuffing box would leak excessively
A.gravity and feed oil cups
B.grease cups
C.hand during installation
D.leakage through the stuffing box
A.a needle gun
B.soap and water
C.a wire brush
D.a chipping hammer
A.Hydrochloric acid
B.Chlorine
C.Sulfuric acid
D.Zinc chromate
A.absolute humidity
B.relative humidity
C.specific humidity
D.total humidity
A.excessive pump speed
B.excessive suction head
C.worn wearing rings
D.gross pump misalignment
A.Distillation is the process of boiling seawater to produce vapor which is condensed into fresh water
B.Evaporation is the second part of the distillation process where brine is removed
C.Brine is the result of condensed sea water vapor
D.Distillate is the product resulting from the evaporation of fresh water vapor
A.absolute humidity
B.specific humidity
C.effective humidity
D.relative humidity
最新试题
A salinity indicator is used to determine the （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
Thermostatic expansion valves can be adjusted for （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
Which of the following statements is correct concerning heat transfer?（）
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
A salinity indicator is used to determine the （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.